Epidemiological aspects of multiple sclerosis.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003710:Demography; D005191:Family Characteristics; D006801:Humans; D007557:Israel; D008393:Marriage; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000235:genetics; D009674:Nova Scotia; D011051:Poliomyelitis / Q000453:epidemiology; D012424:Rural Population; D012923:Social Class; D006113:United Kingdom; D014481:United States; D014505:Urban Population